Grasping fingers

ABSTRACT

Improved inflatable grasping or picking fingers forming articlegrasping elements for handling various articles, such as in the picking of fruit from trees or transferring fruit or food from one conveyor to another or depositing the same within containers, each finger having a rigid support or &#39;&#39;&#39;&#39;bone&#39;&#39;&#39;&#39; and tie means for limiting the radial distention of the finger from the support when it is inflated. In one form of the invention, the outer covering of the finger is connected to the central support by flexible threads or strands. In another form, the outer covering is connected to the central support by a web of sheet fabric disposed transversely or longitudinally of the support. In still another form, the outer contour of the finger is defined by the free portions of a plurality of sections or chambers of flexible material. In one form the sections are partitioned longitudinally of the central support with provision for individually selectively inflating the sections. In another form, the sections are substantially coextensive with and disposed circumferentially about the central support with the longitudinal axes of the sections generally parallel thereto, including means for selectively inflating any or all of the sections; whereby some of the articles being grasped may be dropped while a holding grip is retained on others. In still another form, the sections are partitioned both longitudinally and circumferentially of the central support.

United States Patent Inventor James D. Frost P. 0. Box 775, Porterville, Calif. 93257 Appl. No. 737,557 Filed June 17, 1968 Patented Apr. 13, 1971 GRASPING FINGERS 13 Claims, 11 Drawing Figs.

US. Cl 294/87, 294/92, 294/93 Int. Cl B66c1/10 Field of Search 294/67, 87, 87 (A), 93, 99, 92

References Cited UNITED STATES PATENTS 3,327,450 6/1967 Carter 294/93 3,347,587 10/1967 Frost 294/87 Primary ExaminerI-1arvey C. Hornsby Attorney-Huebner and Worrel ABSTRACT: Improved inflatable grasping or picking fingers forming article-grasping elements for handling various articles, such as in the picking of fruit from trees or transferring fruit or food from one conveyor to another or depositing the same within containers, each finger having a rigid support or bone and tie means for limiting the radial distention of the finger from the support when it is inflated. In one form of the invention, the outer covering of the finger is connected to the central support by flexible threads or strands. In another form, the outer covering is connected to the central support by a web of sheet fabric disposed transversely or longitudinally of the support. In still another form, the outer contour of the finger is defined by the free portions of a plurality of sections or chambers of flexible material. In one form the sections are partitioned longitudinally of the central support with provision for individually selectively inflating the sections. In another form, the sections are substantially coextensive with and disposed circumferentially about the central support with the longitudinal axes of the sections generally parallel thereto, including means for selectively inflating any or all of the sections; whereby some of the articles being grasped may be dropped while a holding grip is retained on others. In still another form, the sections are partitioned both longitudinally and circumferentially of the central support.

PATENTED APR 1 31971 sum 2 OF 2 JAMES D. FROST INVENTUR A TTORNEYS GRASPING FINGERS BACKGROUND OF INVENTION This invention relates to apparatus for handling foods and fruits of the type employed for transferring fruit from one location to another such as picking fruit from trees, or transferring fruit from one conveyor to another or depositing the fruit within containers, cartons, crates, or boxes and the like, and more particularly to improvements in inflatable picking fingers which grasp or seize the fruit with a sufficient force to achieve the transferring, yet the grasping force is not so great as to bruise or otherwise damage the fruit or food so as to render the same unsightly or inedible.

The general type of article-handling apparatus referred to is shown and described in US. Pat. No. 3,347,587 in which the article is grasped by a plurality of inflatable fingers including essentially a central support or bone" and a flexible outer covering divided into sections by means of spaced circumscribing collars or bands, each section of finger being inflated or distended by means of pressurized air passing through the central support and discharged through suitably spaced ports which are in communication with the finger sections. While the apparatus of the aforementioned patent has been very effective in the handling of food and fruit, further dependability and standardization of operations is desired, particularly with respect to predetermining the maximum distention thereof.

SUMMARY OF INVENTION It is therefore an object of the present invention to provide improved grasping fingers in an article-handling apparatus.

Another object is to provide improved grasping fingers in an article-handling apparatus which fingers are inflatable and distend radially with inflation but are inherently limited in the amount of such radial distention.

A further object is to provide improved fingers of the character referred to in which each finger is made up of flexible sections in communication with each other and each finger is inflatable for progressively radially distending the finger from the base to the distal end thereof.

Still another object is to provide an improved grasping finger in an article-handling apparatus which is sectionalized longitudinally of the central support of the finger and includes inflation mechanisms for radially distending the sections for the grasping of articles.

A still further object is to provide an improved grasping or picking finger which is made up of a plurality of elongated sections circumferentially disposed about a central support having inflation means for selectively inflating one or all of the longitudinal sections for the purpose of dropping out some articles while retaining others. a

An additional object is to provide an improved grasping finger which is made up of sections partitioned both longitudinally and circumferentially of the central support for varied application.

These and other objects and advantages are achieved by an improved grasping finger having an elongated, substantially rigid central support and an outer covering of suitable laminated flexible material surrounding the central support and inflatable for causing the covering to distend outwardly from the central support and is connected thereto in a manner limiting such outward distention. In one instance, the distention is limited by means of flexible threads or strands and in another by webs of material disposed in planes transversely of the longitudinal axis of the central support or in planes intersecting generally at or in the vicinity of the longitudinal axis of the central support. In the case of the fonner, the finger is divided up into a plurality of sections disposed along the central support with inflating mechanisms for progressively or selectively individually inflating the sections. In the case of the latter, the finger is made up of a plurality of longitudinally extending sections disposed circumferentially about the central support which is provided with air passageways for selectively extending any one or all of the longitudinal sections. In still another form of the finger, both features are combined.

I BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a fragmentary longitudinal section illustrating a finger of the present invention in inflated condition.

FIG. 2 is a fragmentary cross section illustrating a plurality of fingers of the present invention grasping an article therebetween and showing the means for limiting distention of the fingers.

FIG. 3 is a cross section on a larger scale of a finger of the present invention showing a different manner for limiting the distention of the finger.

FIG. 4 is a fragmentary longitudinal sectional perspective view of a finger of the present invention showing still another manner of limiting the distention thereof.

FIG. 5 is a fragmentary longitudinal section of another finger of the present invention in which the finger is partitioned into sections disposed along the central support thereof.

FIG. 6 is a view somewhat similar to FIG. 5 but illustrating the manner of selectively individually inflating the sections of the finger.

FIG. 7 is a fragmentary perspective view of a form-of the finger of the present invention in which tfie finger is defined by a plurality of elongated chambers extending substantially coextensively with the central support of the finger and disposed circumferentially therearound.

FIG. 8, 9 and 10 are cross sections illustrating various forms of the central support of the finger and illustrating the manner of selectively individually inflating each of the sections or chambers.

FIg. 11 is a perspective view of a finger in which the elongated air chambers are partitioned into sections along the central support, the sections of one chamber being staggered with respect to the sections of adjacent chambers.

DESCRIPTION OF EMBODIMENTS Referring to Fig. I, there is illustrated an improved picking finger embodying the principles of the present invention designated generally by reference numeral 20. Finger 20 includes a substantially rigid central support or bone in the form of a tubular support or tube 22 and disposed thereabout is an envelope 24, preferably of fabric and elastomer materials laminated as described in the aforementioned US. Pat. No. 3,347,587. Tube 22 extends through a sleeve 26 supported in base plates 28 and 30. Tube 22 may be mounted for rotation in the sleeve 26, rotation being imparted thereto by a collar 32 fixed to the support 22 and having an actuating lever 34. Adjacent plate 28 is a band or collar 36 which secures one end of the envelope 24 to the tubular support 22.

Tube 22 is disposed substantially perpendicularly to plates 28 and 30 and is provided with a plurality of apertures or ports 38 which communicate the interior of the tube with the interior of the finger envelope 24, the distal end of the tube being closed. The other end of the tube 22 is adapted to be connected to a source of pressurized air, not shown. Thus, the introduction of air into the envelope 24 through the ports 38 inflates and distends the same to engage with an article 40.

Inviting attention also to FIg. 2, it will be noted that the envelope 24 is connected or tied to the central tubular support 22 by tie means in the form of generally radially extending strands or threads 42 of a material which is flexible but has a limited elastic modulus for limiting the extent to which the envelope is distended upon inflation of the finger. The distal ends of the threads 42 are suitably secured to the envelope 24 as by bonding or the like and the inner ends of the threads are conveniently connected to a plurality of bands or collars 44 circumscribing the tube 22 at longitudinally spaced points therealong. As seen in FIG. 2, upon inflation of the fingers 20 with an article 40 disposed therebetween, the finger envelopes 24 are distended, such distention being limited by the threads or strands 42 but deformation of the envelopes and threads is permitted to grasp and retain the article 40.

FIG. 3 illustrates another manner of interconnecting the central tube 22 and the finger envelope 24 in which a plurality of threads or strands 42' extend transversely of the tubular support and have the midpoints 44' thereof bonded or otherwise secured to the tube, the distal ends of the threads being bonded or otherwise secured to the finger envelope 24.

As shown in FIG. 4, there is illustrated another form of a grasping finger in accordance with the present invention designated generally by reference numeral 200 which is essentially the same as finger 20 except that the threads or strands 42 are replaced with a web or disc of sheet material 46 which is flexible but has limited radial elasticity for limiting distention of the envelope 24 upon inflation of the finger. Discs 46 serve, in effect, to divide the envelope into sections longitudinally of the support 22 and the disc at the base of the finger may be reinforced by a flanged collar 36'. The interior discs may be apertured, as at 48, to provide communication between the sections. If desired, the number of ports 38 in the tube 22 may be limited in order that the sections of the finger envelope may be progressively inflated in either direction from the point of introduction of air into a selected section. FIG. 4 also illustrates a protective device for the picking finger which may be a cap 50 of flexible but durable material, such as plastic, having the general shape of a surface of a cone with a rounded apex.

FIG. 5 illustrates a finger 20b which is essentially like finger 200 but has a finger envelope which is defined by a plurality of members or sections 24b each having an inwardly directed annulus forming an end wall 46' at each end thereof provided with an annular flange or collar 52 adapted to circumscribe tube 22 and be bonded or otherwise secured thereto. Members 24b may be mounted on the tube 22 with adjacent end walls 46' in contact and bonded to each other, the contiguous end walls being apertured as at 48 to provide communication between the interiors of the members 24b or the contiguous end walls 46 may be left unapertured and unbonded to each other and each member 24b may be individually inflated through a port 38 in tube 22 in communication therewith. Flanged collars 36 serve to reinforce or back up the end walls 46 of the end section members 24b.

FIG. 6 illustrates a finger 20c the contour of which is defined by a plurality of envelope sections 24c individually secured to a central support or tube 22c and individually inflatable through an air conduit individual thereto. Thus, the envelope section 240 at the base of the finger 200 is adapted to be inflated through an air conduit 380, the next envelope section through an air conduit 38b, and so on, air conduit 38m serving to inflate the distal envelope section 240. With such an arrangement, the envelope sections 240 may be progressively distended by inflation or only selected envelope sections may be inflated, as desired. For example, where fingers 200 are part of an apparatus operating to pick up a layer of articles and deposit them in a packing case, only the distal envelope sections at the ends of the tubes 22c need be inflated, resulting in a more rapid inflation and deflation with a consequent saving in the amount of air required. Also, where some sections are exposed to greater wear and require replacement, only the worn sections need to be replaced rather than the whole envelope of the finger. Finger 20c may be provided with a collar 36' to reinforce section 240 at the base thereof and a protective cap 50' at its distal end.

Additionally, with the fingers 20c operated to inflate all the envelope sections 24c thereof, thereby grasping several layers of articles, the envelope sections may be deflated layer by layer in order that the first layer may be placed in one container, the next layer in another container, and so on.

Another form of picking finger 20d in accordance with the present invention is illustrated in FIG. 7. Finger 20d includes a central support or tube 22d suitably supported in base plates 28' and 30". Disposed about the support 22d are envelope sections 24d of elongated form which are substantially coextensive with the support and held thereon by a retaining collar 36. It will be noted that each envelope section 24d has a substantially sectorlike cross section with inwardly directed sheet portions 54 interconnected by a web portion 56, portions 54 being substantially disposed in radially extending planes intersecting generally at the central longitudinal axis of the support 22d, the web portion 56 being suitably bonded or otherwise secured to the support 22d and suitably apertured or ported as at 38a to provide communication between the interior of the envelope section 24d and the air passageway through the support 22d. In lieu of such communication, apertures 38a and ports in the support 22d may be omitted and each of the envelope sections 24d individually inflated by individual conduits 58.

Alternatively, as seen in FIG. 8, each of the envelope sections 24d can be individually inflated by employing partitions 60 inside the central tubular support 22d to provide individual air passageways in communication with apertures or ports 38a individual to the sections. The same effect can be obtained employing concentric tubes 60t as shown in FIG. 9, the central tubular support 22c in this case being cylindrical. However, it is to be understood that the central support may be of any desired cross section suitably partitioned to provide the number of air passageways required or desired. For example, the central tubular support can be square, or of hexagonal cross section 22c, as shown in FIG. 10, and have the interior thereof subdivided by partitions 60p with each of the sides of the hexagon having an envelope section 24e secured thereto. Thus, the central supports shown are exemplary only and are not limited to such forms since obviously the cross section of a central support can be polygonal or arcuate, circular or noncircular, as necessary or desirable.

FIG. 11 illustrates a fonn of picking finger 20f in accordance with the present invention which is a composite of the forms of fingers illustrated in FIGS. 6 and 7. Viewing FIG. 11, it will be noted that the contour of the finger is defined by a plurality of envelope sections 24f which are placed in endto-end relation on central support or tube 22f to give the effect of an elongated envelope section similar to envelope section 24d of FIG. 7 which is substantially coextensive with the tube. A plurality of such sections are disposed about the tube 22f in staggered relationship to define the finger contour. The interior of tube 22f may be suitably partitioned to provide a sufficient number of air passageways for individually and selectively inflating the several sections as desired.

The finger of FIG. 6 is shown as having a protective cap 50'. It will be appreciated that the fingers of FIGS. 7l1 can have such a cap as well.

OPERATION The operation of the grasping or picking fingers of the present invention is believed to be clearly apparent and is briefly summarized at this point. Turning to FIGS. 1 and 2, fingers 20 in deflated condition thereof are inserted among articles to be picked or grasped and the fingers are inflated to distend the envelopes 24 thereof, such distention being limited by the length of the threads or strands 42. This prevents translation of the axes of the envelopes and in effect provides a reaction for the exertion of pressure on that part of the envelope deformed by engagement with an article, whereby the article is grasped with a firm gentle grip which is releasable upon deflation of the fingers. In the forms of the fingers which are sectioned, by selective inflation and deflation, articles may be selectively grasped, after which some may have the grip thereon released for dropping the same at one point or in a layer, while retaining the grip on the remaining articles for further handling.

There have, thus, been provided novel picking fingers of improved form which may be variously formed to provide varied application thereof for different handling of articles.

Although the invention has been herein shown and described in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

lclaim:

l. A grasping finger for use in apparatus adapted to grasp discrete articles disposed between a plurality of such elements, comprising an elongated substantially rigid support, a distendable elongated envelope having an outer grasping portion circumscribing said support and of a length substantially coextensive therewith, and tie means within the envelope interconnecting said portion and said support for limiting the extent to which said envelope can be radially displaced from said support.

2. The finger of claim 1 wherein said tie means comprises flexible strands of substantially fixed length;

3. The finger of claim 1 wherein said tie means comprises a sheet of flexible material.

4. The finger of claim 3 wherein said sheet of flexible material is disposed transversely of said support.

5. The finger of claim 1 wherein said tie means comprises sheets of flexible material disposed in longitudinally spaced relation on said support and extending transversely thereof.

6. The finger of claim 5 wherein said transversely extending sheets of flexible material have apertures therein.

7. The finger of claim 1 wherein one end of said envelope is provided with protective means.

8. An article-grasping device comprising a plurality of elongated radially distendable fingers between which relatively fragile articles can be grasped, each of said fingers having an elongated substantially rigid support; an envelope of somewhat flexible material mounted on the support; and tie means within said envelope interconnecting the envelope and said support for limiting the extent to which the fingers are deformed incident to article engagement to insure dependably firm but gently gripping of such articles while precluding engagement of the articles against said rigid supports.

9. The device of claim 8 in which said tie means comprises a sheet of flexible material of substantially fixed radial dimensions.

10. The device of claim 9 in which said sheet of flexible material is disposed transversely of said support.

11. The device of claim8 in which said tie means comprises a plurality of flexible sheets disposed in longitudinally spaced relation along said support and being transversely extended therefrom a predetermined substantially fixed radial dimension.

12. The device of claim 11 including a plurality of per apertures in said sheets.

'13. An article-grasping device comprising a plurality of elongated radially distendable fingers between which relatively fragile articles can be grasped, each of said fingers having an elongated substantially rigid support; means mounting the supports in substantially fixed spaced relation; inflatable envelopes of flexible material individually mounted on the supports having external article engaging surfaces; means for inflating said envelopes; and flexible tie means within said envelopes interconnecting their respective envelopes and their supports for limiting the extent to which the fingers are deformable at and adjacent to the positions of connection of the tie means thereto to preclude excessive radial displacement of the envelopes relative to their respective supports to insure optimum cushioning of the articles being grasped. 

1. A grasping finger for use in apparatus adapted to grasp discrete articles disposed between a plurality of such elements, comprising an elongated substantially rigid support, a distendable elongated envelope having an outer grasping portion circumscribing said support and of a length substantially coextensive therewith, and tie means within the envelope interconnecting said portion and said support for limiting the extent to which said envelope can be radially displaced from said support.
 2. The finger of claim 1 wherein said tie means comprises flexible strands of substantially fixed length.
 3. The finger of claim 1 wherein said tie means comprises a sheet of flexible material.
 4. The finger of claim 3 wherein said sheet of flexible material is disposed transversely of said support.
 5. The finger of claim 1 wherein said tie means comprises sheets of flexible material disposed in longitudinally spaced relation on said support and extending transvErsely thereof.
 6. The finger of claim 5 wherein said transversely extending sheets of flexible material have apertures therein.
 7. The finger of claim 1 wherein one end of said envelope is provided with protective means.
 8. An article-grasping device comprising a plurality of elongated radially distendable fingers between which relatively fragile articles can be grasped, each of said fingers having an elongated substantially rigid support; an envelope of somewhat flexible material mounted on the support; and tie means within said envelope interconnecting the envelope and said support for limiting the extent to which the fingers are deformed incident to article engagement to insure dependably firm but gently gripping of such articles while precluding engagement of the articles against said rigid supports.
 9. The device of claim 8 in which said tie means comprises a sheet of flexible material of substantially fixed radial dimensions.
 10. The device of claim 9 in which said sheet of flexible material is disposed transversely of said support.
 11. The device of claim 8 in which said tie means comprises a plurality of flexible sheets disposed in longitudinally spaced relation along said support and being transversely extended therefrom a predetermined substantially fixed radial dimension.
 12. The device of claim 11 including a plurality of per apertures in said sheets.
 13. An article-grasping device comprising a plurality of elongated radially distendable fingers between which relatively fragile articles can be grasped, each of said fingers having an elongated substantially rigid support; means mounting the supports in substantially fixed spaced relation; inflatable envelopes of flexible material individually mounted on the supports having external article engaging surfaces; means for inflating said envelopes; and flexible tie means within said envelopes interconnecting their respective envelopes and their supports for limiting the extent to which the fingers are deformable at and adjacent to the positions of connection of the tie means thereto to preclude excessive radial displacement of the envelopes relative to their respective supports to insure optimum cushioning of the articles being grasped. 